In the past month, ENSO-neutral conditions persisted, with sea surface temperatures (SSTs) near average over most of the equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño index values ranged from -0.1°C to +0.4°C [Fig. 2]. Subsurface ocean temperatures were near-to-above average (averaged across 180°-100°W, [Fig. 3]), with above-average subsurface ocean temperatures at depth in the central and western Pacific [Fig. 4]. For the month, low-level winds were easterly over the east-central Pacific, while upper-level winds were mostly near average across the equatorial Pacific Ocean. Convection was enhanced over Indonesia [Fig. 5]. Collectively, the coupled ocean-atmosphere system in the tropical Pacific reflected ENSO-neutral.

The IRI and North American Multi-Model Ensemble predictions indicate ENSO-neutral is most likely through the Northern Hemisphere winter 2025-26 [Fig. 6]. The forecast team also continuously favors ENSO-neutral through early 2026, with smaller chances that La Niña could form during winter 2025-26. In summary, ENSO-Neutral is likely in the Northern Hemisphere summer 2025 (82% chance in June-August) and may continue into winter 2025-26, though confidence is lower (48% chance of Neutral and 41% chance of La Niña in November-January; [Fig. 7]).